Measurements:
°C
°F
CURRENT WEATHER
10:27
Key West
88°F
W 12 mph
Feels like: 98°F
Precip: 47%
World Resorts USA Key West Weather

7 Day Weather Forecast

09.15
tue
DAY
88°F
W 9 mph
precip
18%
NIGHT
90°F
W 19 mph
precip
16%
09.16
wed
DAY
90°F
W 16 mph
precip
16%
NIGHT
90°F
W 19 mph
precip
26%
09.17
thu
DAY
90°F
W 12 mph
precip
24%
NIGHT
90°F
W 17 mph
precip
15%
09.18
fri
DAY
84°F
N 13 mph
precip
78%
NIGHT
88°F
W 15 mph
precip
17%
09.19
sat
DAY
88°F
NW 4 mph
precip
22%
NIGHT
88°F
NW 8 mph
precip
18%
09.20
sun
DAY
88°F
N 4 mph
precip
18%
NIGHT
88°F
NW 6 mph
precip
7%
09.21
mon
DAY
88°F
N 3 mph
precip
16%
NIGHT
90°F
W 9 mph
precip
12%

Key West Sea Water Temperature in September, °F

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Key West was 31.5°F. The maximum and minimum values were 31.0°F and 31.9°F respectively.

Key West on the Weather Map

Best Time to Visit Key West
The most sunny months:
May 17 days
March 16 days
April 16 days
The most warm months:
August 91.5 °F
July 91.0 °F
September 89.7 °F
Warmest sea temperature:
August 91.4 °F
July 90.8 °F
September 90.1 °F
The most cold months:
January 74.4 °F
February 76.3 °F
December 78.2 °F
The most rainy months:
June 7 days
August 7 days
September 6 days
The most windy months:
November 14 mph
December 14 mph
January 14 mph
more details